Re outliers

[Kornbrot, Diana]

This scenario probably means that they are not ‘outliers’ bt an intrinsic part of a non-normal distribtion

Try transformations e.g. Log, or box and cox
But as bruce says, tehn look for multivariat oltliers
Re: Detecting outliers; when to stop? This scenario probably means that they are not ‘outliers’ bt an intrinsic part of a non-normal distribtion
Try transformations e.g. Log, or box and cox
But as bruce says, tehn look for multivariat oltliers
Best
diana


On 16/04/2012 15:34, "Bruce Weaver" <MailScanner has detected a possible fraud attempt from "bruce.weaver@..." claiming to be bruce.weaver@... <http://bruce.weaver%40hotmail.com> > wrote:

noxeon wrote
>
> So I have detected some outliers in my data and removed them, however when
> I removed them all, new ones appeared in bloxplot, should I keep removing
> until there is none or just once is enough?
>

What's the variable (or variables)?  Have you ruled out data entry errors?

What kind of analysis are you doing, some kind of regression model?  If so,
I'd be more concerned about multivariate outliers and influential points
than univariate outliers.  Cook's distance is one well-known measure of
influence you could look at.

HTH.


-----
--
Bruce Weaver
bweaver@... <http://bweaver%40lakeheadu.ca>
http://sites.google.com/a/lakeheadu.ca/bweaver/

"When all else fails, RTFM."

NOTE: My Hotmail account is not monitored regularly.
To send me an e-mail, please use the address shown above.

--
View this message in context: http://spssx-discussion.1045642.n5.nabble.com/Detecting-outliers-when-to-stop-tp5642233p5643995.html
Sent from the SPSSX Discussion mailing list archive at Nabble.com.

=====================
To manage your subscription to SPSSX-L, send a message to
LISTSERV@... <http://LISTSERV%40LISTSERV.UGA.EDU>  (not to SPSSX-L), with no body text except the
command. To leave the list, send the command
SIGNOFF SPSSX-L
For a list of commands to manage subscriptions, send the command
INFO REFCARD

Best

diana

---

Emeritus Professor Diana Kornbrot
email:  d.e.kornbrot@...    
web:    http://dianakornbrot.wordpress.com/
Work
School of Psychology
 University of Hertfordshire
 College Lane, Hatfield, Hertfordshire AL10 9AB, UK
 voice:   [phone]
   fax:     [phone]
Home
 19 Elmhurst Avenue
 London N2 0LT, UK
    voice:   [phone]
    mobile: [phone]